Our world today seems to teach us that if we are Christians, we must hate everyone who does not do as the Bible instructs.
This view is ironic, because Christians are to love their enemies (Matthew 5:44); our enemies would be anyone who we hate, right?
2 Thessalonians 3:14,15 (NASB): "If anyone does not obey our instruction in their letter, take special note of that person and do not associate with him....Yet, do not regard him as an enemy, but admonish him as a brother."
According to this passage, Christians are to not be best friends with those who are not Christ followers, but we are not to treat them as our enemies. That, I believe, is where the Christians are getting a negative reputation. We have accepted the world's view that if we do not agree with someone's choices, we must speak out negatively against them and then not associate with them at all.
We are to love everyone, especially our enemies and even more so those we do not agree with.